(a) Field
The described technology relates generally to a signaling method. More particularly, the described technology relates generally to a signaling method in a wireless local area network (WLAN).
(b) Description of the Related Art
A WLAN is being standardized by the IEEE (Institute of Electrical and Electronics Engineers) Part 11 under the name of “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications.”
After an original standard was published on 1999, new version standards are continuously published by amendments. The IEEE standard 802.11a (IEEE Std 802.11a-1999) supporting 2.4 GHz band was published on 1999, and the IEEE standard 802.11g (IEEE Std 802.11g-2003) supporting 5 GHz band was published on 2003. These standards are called legacy. Subsequently, the IEEE standard 802.11n (IEEE Std 802.11n-2009) for enhancements for higher throughput (HT) was published on 2009, and the IEEE standard 802.11ac (IEEE 802.11ac-2013) for enhancements for very high throughput (VHT) was published on 2013. Recently, a high efficiency WLAN (HEW) for enhancing the system throughput in high density scenarios is being developed by the IEEE 802.11ax task group.
In such WLAN scenarios, a transmitting device transmits a frame having a signal field including signaling information to allow a receiving device to successfully receive and decode the frame. When the signaling information is increased, the number of symbols included in the signal field is required to be increased. However, if the number of symbols included in the signal field is increased, a minimum length of a frame is increased such that the transmission efficiency is deteriorated. Accordingly, a scheme for additionally transmitting the signaling information is required without increasing the number of symbols.